Reaplacing text in JTextField

[PhQ]

Hey, how can I replace bad characters in JTextField ?
For example if the user enters "%$&^&hello^%$%^ " it will the place it to "hello".

[Fubarable]

You can possibly use String#replaceAll(String regex, String replacement), but you have to have a very good idea of just what constitutes "bad characters".

[PhQ]

Is it possible to make it a char array for it or it has to be just a string?

[Fubarable]

Is it possible to make it a char array for it or it has to be just a string?

You can certainly change a String to a char array by a simple method and can do this if you like, but I like the regex capabilities of String. Why do you want to do this? You may wish to go into greater detail about your problem.

[PhQ]

I'm making a registration form, and I've made an account with an username like this: 435345"), and when I've tried to login it just didn't log me in. Uhh its hard to explain...
For example my username was : phq.
I have made a new account : 23423")
When I try to login on to phq it just doesn't do it.
Basically I need it for security reasons.

[PhQ]

I would post my whole program, but it's 1262 lines.